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• ffmpeg .iff image sequence to video

  3 septembre 2013, par rajat

  I have a file sequence of format test2#.iff, and i want to convert this sequence to a video, i have tried following commands:

  ffmpeg -f IFF -r 25 -start_number 75 -i "test2%d.iff" -vcodec libx264 test2.mp4
  Error: test2%d.iff: No such file or directory
  
  ffmpeg -f image2 -r 25 -start_number 75 -i "test2%d.iff" -vcodec libx264 test2.mp4
  Error: [image2 @ 00000000002ee220] Could not find codec parameters for stream 0 (Video: none): unspecified size Consider increasing the value for the 'analyzeduration' and 'probesize' options test2%d.iff: could not find codec parameters
  

  I also have tried various codecs but it gives me same errors, can any of you please shed some light on what might be wrong?

• How to concat two/many mp4 files(Mac OS X Lion 10.7.5) with different resolution, bit rate [on hold]

  3 septembre 2013, par praveen

  I have to concat different mp4 files into single mp4 file. i am using following ffmpeg command but this command is only working if both file is same(copy, or if all video property is same(codec, resolution,bitrate....) ) other wise result is unexpected video. (I am working on Mac OS X Lion 10.7.5)

  ffmpeg commad:

  ffmpeg -i images/1/output.mp4 -c copy -bsf:v h264_mp4toannexb -f mpegts intermediate1.ts
  ffmpeg -i images/1/Video2.mp4 -c copy -bsf:v h264_mp4toannexb -f mpegts intermediate2.ts
  ffmpeg -i "concat:intermediate1.ts|intermediate2.ts" -c copy -bsf:a aac_adtstoasc output2.mp4
  

  console output:

  [mpegts @ 0x7f8c6c03d800] max_analyze_duration 5000000 reached at 5000000 microseconds
  
  Input #0, mpegts, from 'concat:intermediate1.ts|intermediate2.ts':
  Duration: 00:00:16.52, start: 1.400000, bitrate: 1342 kb/s
  Program 1 
  Metadata:
  service_name    : Service01
  service_provider: FFmpeg
  Stream #0:0[0x100]: Video: h264 (Main) ([27][0][0][0] / 0x001B), yuv420p, 1024x768 [SAR   1:1 DAR 4:3], 25 fps, 25 tbr, 90k tbn, 50 tbc
  Stream #0:1[0x101](und): Audio: aac ([15][0][0][0] / 0x000F), 48000 Hz, stereo, fltp, 101 kb/s
  
  
  
  Output #0, mp4, to 'output2.mp4':
  Metadata:
  encoder         : Lavf54.63.104
  Stream #0:0: Video: h264 ([33][0][0][0] / 0x0021), yuv420p, 1024x768 [SAR 1:1 DAR 4:3],      q=2-31, 25 fps, 90k tbn, 90k tbc
  Stream #0:1(und): Audio: aac ([64][0][0][0] / 0x0040), 48000 Hz, stereo, 101 kb/s
   Stream mapping:
  Stream #0:0 -> #0:0 (copy)
  Stream #0:1 -> #0:1 (copy)
  Press [q] to stop, [?] for help
   frame=  586 fps=0.0 q=-1.0 Lsize=    2449kB time=00:00:20.11 bitrate= 997.4kbits/s    
   video:2210kB audio:225kB subtitle:0 global headers:0kB muxing overhead 0.578335%
  

  Please help

• Compile FFMPEG Using Eclipse Android

  3 septembre 2013, par Ivelius

  NDK experts , I need your help...

  My goal is to easily compile ffmpeg library using android NDK and eclipse.

  What I usally do when I want to develop using NDK , is right click on android project in eclipse ->Android Tools -> Add Native support. And Everything works and compiles. Every time I want to build my project , I just hit "Build" button (with a hammer icon on it).

  Now I just need to add all ffmpeg libraries and run a simple program like this. I downloaded latest ffmpeg libraries from official website.I've extracted downloaded content into JNI library . And when I try to build , I get countless errors. Something like "fatal error: libavutil/avconfig.h: No such file or directory" ...

  My Android.mk file looks like this :

  LOCAL_PATH := $(call my-dir)
  
  include $(CLEAR_VARS)
  include $(call all-subdir-makefiles)
  
  LOCAL_MODULE    := HELLONDK
  LOCAL_SRC_FILES := hello-ndk.cpp
  
  include $(BUILD_SHARED_LIBRARY)
  

  EDIT : I've been looking for a solution for a few days before posting this question.

• ffmpeg time unit explanation and av_seek_frame method

  3 septembre 2013, par user325320

  What does time_base mean in ffmpeg? document(here) says it is "frames per second". and I see in a real example that:

  AVFormatContext->streams[video_index]->time_base == 1 / 30000

  But video's AVCodecContext->time_base == 1001 / 60000

  This makes me quite confused, and I don't understand them.

  The second question is about av_seek_frame method. If seeking via time stamp (last parameter is AVSEEK_FLAG_BACKWARD or 0), the seek is started from current position read by av_seek_frame? or from the start of the file? or from the start position of decoding after last av_seek_frame call ?

• ffmpeg + play video loop

  3 septembre 2013, par Javier Ramírez

  Does anyone know how to make a video using ffmpeg + Opengl play continuously?. Because this is only played once

  tiempo = glfwGetTime();
  duracion = 1.0/25.0; // 1 second / 25 fps
  
  while(1){
  
  ...        
  
    if(glfwGetTime() > tiempo + duracion){
      if(av_read_frame(pFormatCtx,&packet) >= 0){
        if(packet.stream_index == 0){
          avcodec_decode_video2(pCodecCtx,pFrame,&frameFin,&packet);
          if(frameFin)sws_scale(img_convert_ctx,pFrame->data,pFrame->linesize,0,pCodecCtx->height,pFrameRGB->data,pFrameRGB->linesize);
        }
        av_free_packet(&packet);
      }
      tiempo += duracion;
    }
  
  ...
  
  }
  

  I know av_read_frame function (...) returns 0 if the end of file. But how do I make the function again returns a value other than zero? o How I can I make the video is constantly repeated?